A scleral depressor is used to facilitate examination of a fundus of an eye, particularly its periphery. During an ocular fundus examination, and particularly during the study of areas of the retina such as the periphery, it is necessary to control the position of the eye. Several sclera depressors have been designed for this purpose. For example, the Storz Instrument Company catalog illustrates several such depressors. These scleral depressors include bulbous or ball end depressors, T-bar depressors, ring depressors, and flat spatula depressors.
The instruments disclosed in the prior art comprise a handle, with optional pocket clip, which is attached to the blade either straight or at an offset angle to facilitate manipulation of the blade from a position that leaves the field substantially clear for the simultaneous use of other instruments, such as an opthalmoscope.
U.S. Pat. No. 4,453,546 discloses a scleral depressor for controlling eye position that has a substantially oblong-shaped blade. The blade has a textured surface with a hole substantially in the middle of the blade. In operation, the blade is manipulated by the operator to depress against the sclera of a patient's eye for either rotating or immobilizing the globe of the eye during examination.
U.S. Pat. No. 6,440,065 discloses an eyelid speculum and scleral depressor for controlling eye position by pressing against the sclera of the eye with a depressor. The scleral depressor has an elongated handle portion, two stem portions and two blades. The blades are flat and substantially paddle-shaped.
In addition to these more conventional prior art devices, some unconventional means, such as paper clips, safety pins, cotton tipped applicators and strabismus hooks are used for the above stated purposes. These type of scleral depressors are not ideally suited for examination for the following general reasons: (a) the tips of these depressors are bulky and with a pediatric lid speculum in place it is often difficult to find adequate room to insert an instrument into the conjunctival sac; (b) undue pressure on the globe and compromise of the ocular circulation is therefore possible; and (c) these scleral depressors have smooth surfaces, slide on the globe, and will not rotate it to different examination positions.
Additionally, both the conventional and unconventional scleral depressors are often difficult to use in conjunction with other instruments because they are not designed for operation from a position which will leave the field substantially clear for the simultaneous use of these instruments in the examination of the eye.